Wiley最新文献

Salt stress constrains the development and growth of plants. To tolerate it, mechanisms of endocytosis and vacuolar compartmentalization of Na⁺ are induced. In this work, the genes that encode a putative activator of vesicular trafficking called MON1/CCZ1 from Solanum chilense, SchMON1 and SchCCZ1, were co-expressed in roots of Arabidopsis thaliana to determine whether the increase in prevacuolar vesicular trafficking also increases the Na⁺ compartmentalization capacity and tolerance. Initially, we demonstrated that both SchMON1 and SchCCZ1 genes rescued the dwarf phenotype of both A. thaliana mon1-1 and ccz1a/b mutants associated with the loss of function, and both proteins colocalized with their functional targets, RabF and RabG, in endosomes. Transgenic A. thaliana plants co-expressing these genes improved salt stress tolerance compared to wild type plants, with SchMON1 contributing the most. At the sub-cellular level, co-expression of SchMON1/SchCCZ1 reduced ROS levels and increased endocytic activity, and number of acidic structures associated with autophagosomes. Notably, greater Na⁺ accumulation in vacuoles of cortex and endodermis was evidenced in the SchMON1 genotype. Molecular analysis of gene expression in each genotype supported these results. Altogether, our analysis shows that root activation of prevacuolar vesicular trafficking mediated by MON1/CCZ1 emerges as a promising physiological molecular mechanism to increase tolerance to salt stress in crops of economic interest.

As the single link between leaves and the rest of the plant, petioles must develop conductive tissues according to the water influx and sugar outflow of the leaf lamina. A scaling relationship between leaf area and anatomical traits of xylem and phloem is expected to improve the efficiency of these tissues. However, the different constraints compromising the functionality of both tissues (e.g., risk of cavitation) must not be disregarded. Additionally, deciduous and evergreen plants may have different strategies to produce and package their petiole conduits to cope with environmental restrictions. We explored in 33 oak species the relationships between petiole anatomical traits, leaf area, stomatal conductance, and photosynthesis rate. Results showed allometric scaling between anatomical structure of xylem and phloem with leaf area. We also found correlations between photosynthesis rate, stomatal conductance, and anatomical traits in the petiole. The main novelty is how oaks present a different strategy depending on the leaf habit. Deciduous species tend to increase their diameters to achieve greater leaf-specific conductivity. By contrast, evergreen oaks develop larger xylem conductive areas for a given leaf area than deciduous ones. This trade-off between safety-efficiency in petioles has never been attributed to the leaf habit of the species.

Soybean (Glycine max) is the single most important global source of vegetable protein. Yield improvements per unit land area are needed to avoid further expansion onto natural systems. Mesophyll conductance (g_m) quantifies the ease with which CO₂ can diffuse from the sub-stomatal cavity to Rubisco. Increasing g_m is attractive since it increases photosynthesis without increasing water use. Most measurements of g_m have been made during steady-state light saturated photosynthesis. In field crop canopies, light fluctuations are frequent and the speed with which g_m can increase following shade to sun transitions affects crop carbon gain. Is there variability in g_m within soybean germplasm? If so, indirect selection may have indirectly increased g_m during domestication and subsequent breeding for sustainability and yield. A modern elite cultivar (LD11) was compared with four ancestor accessions of Glycine soja from the assumed area of domestication by concurrent measurements of gas exchange and carbon isotope discrimination (∆¹³C). g_m was a significant limitation to soybean photosynthesis both at steady state and through light induction but was twice the value of the ancestors in LD11. This corresponded to a substantial increase in leaf photosynthetic CO₂ uptake and water use efficiency.

Traditional photosynthesis-driven growth models have considerable uncertainties in predicting tree growth under changing climates, partially because sink activities are directly affected by the environment but not adequately addressed in growth modelling. Therefore, we developed a semi-mechanistic model coupling stomatal optimality, temperature control of enzymatic activities and phenology of cambial growth. Parameterized using Bayesian inference and measured data on Picea abies and Pinus sylvestris in peatland and mineral soils in Finland, the coupled model simulates transpiration and assimilation rates and stem radial dimension (SRD) simultaneously at 30 min resolution. The results suggest that both the sink and phenological formulations with environmental effects are indispensable for capturing SRD dynamics across hourly to seasonal scales. Simulated using the model, growth was more sensitive than assimilation to temperature and soil water, suggesting carbon gain is not driving growth at the current temporal scale. Also, leaf-specific production was occasionally positively correlated with growth duration but not with growth onset timing or annual cambial area increment. Thus, as it is hardly explained by carbon gain, phenology itself should be included in sink-driven growth models of the trees in the boreal zone and possibly other environments where sink activities and photosynthesis are both restrained by harsh conditions.

Background: Sarcopenia is thought to be underlined by age-associated anabolic resistance and dysregulation of intracellular signalling pathways. However, it is unclear whether these phenomena are driven by ageing per se or other confounding factors.

Methods: Lean and healthy young (n = 10, 22 ± 3 years, BMI; 23.4 ± 0.8 kg/m²) and old men (n = 10, 70 ± 3 years, BMI; 22.7 ± 1.3 kg/m²) performed unilateral resistance exercise followed by intake of essential amino acids (EAA). Muscle biopsies were collected from the rested and the exercised leg before, immediately after and 60 and 180 min after EAA intake. Muscle samples were analysed for amino acid concentrations, muscle protein synthesis (MPS) and associated anabolic signalling.

Results: Following exercise, peak plasma levels of EAA and leucine were similar between groups, but the area under the curve was ~11% and ~28% lower in Young (p < 0.01). Absolute levels of muscle EAA and leucine peaked 60 min after exercise, with ~15 and ~21% higher concentrations in the exercising leg (p < 0.01) but with no difference between groups. MPS increased in both the resting (~0.035%·h^-1 to 0.056%·h^-1, p < 0.05) and exercising leg (~0.035%·h^-1 to 0.083%·h^-1, p < 0.05) with no difference between groups. Phosphorylation of S6K1^Thr389 increased to a similar extent in the exercising leg in both groups but was 2.8-fold higher in the resting leg of Old at the 60 min timepoint (p < 0.001). Phosphorylation of 4E-BP1^Ser65 increased following EAA intake and exercise, but differences between legs were statistically different only at 180 min (p < 0.001). However, phosphorylation of this site was on average 78% greater across all timepoints in Old (p < 0.01). Phosphorylation of eEF2^Thr56 was reduced (~66% and 39%) in the exercising leg at both timepoints after EAA intake and exercise, with no group differences (p < 0.05). However, phosphorylation at this site was reduced by ~27% also in the resting leg at 60 min, an effect that was only seen in Old (p < 0.01). Total levels of Rheb (~45%), LAT1 (~31%) and Rag B (~31%) were higher in Old (p < 0.001).

Conclusion: Lean and healthy old men do not manifest AR as evidenced by potent increases in MPS and mTORC1 signalling following EAA intake and exercise. Maintained anabolic sensitivity with age appears to be a function of a compensatory increase in basal levels of proteins involved in anabolic signalling. Therefore, our results suggest that age per se does not appear to cause AR in human skeletal muscle.

Aims: This study aimed to identify the distinct change trajectories of the Chinese visceral adiposity index (CVAI) over time and to investigate their associations with risk of type 2 diabetes mellitus (T2DM).

Materials and methods: This study included 52 394 participants from the prospective project, the Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR). The CVAI was calculated using measures of age, body mass index, waist circumference, triglycerides and high-density lipoprotein cholesterol. Latent mixture modelling was conducted to fit distinct trajectory patterns. The logistic regression model was applied to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of T2DM with various CVAI trajectory patterns.

Results: Four distinct CVAI trajectory patterns were identified: low-increasing, moderate-increasing, moderate high-increasing and high-increasing. Compared with low-increasing CVAI, participants with moderate-increasing (OR 1.73, 95% CI 1.49-2.00), moderate high-increasing (3.48, 3.01-4.03) and high-increasing CVAI (5.50, 4.67-6.47) had a significantly increased risk of T2DM. Similar trajectory patterns were identified in both men and women. The ORs (95% CI) for moderate-increasing, moderate high-increasing and high-increasing groups were 3.28 (2.56-4.19), 7.85 (6.09-10.13) and 13.21 (9.98-17.49) in women respectively, and 1.20 (0.99-1.45), 2.18 (1.82-2.62) and 3.60 (2.93-4.43) in men respectively, when compared to the low-increasing CVAI group. Further, significant effect modifications for age, smoking and physical activity (all P_interaction <0.05) were observed in the relationship between CVAI trajectory patterns and T2DM.

Conclusions: Initially high and persistently elevated CVAI is significantly associated with an increased risk of T2DM, with a particular focus on women, younger people, nonsmokers and physically inactive individuals. Continuous monitoring of CVAI levels will benefit effective identification, early intervention and management of individuals at high risk of T2DM.

Aim: To investigate the effect of different physical activity patterns on obesity.

Materials and methods: Data from adults aged 17-79 years were extracted from the Hong Kong Territory-Wide Physical Fitness Survey conducted in 2011-2012 and 2021-2022. Moderate to vigorous physical activity (MVPA) patterns were collected through questionnaires and categorized as inactive (no MVPA ≥10 min), insufficiently active (<150 min MVPA/week), weekend warriors (≥150 min MVPA/week from 1 to 2 days) and regularly active (≥150 min MVPA/week from ≥3 days). The association between these activity patterns with obesity risk and body fat percentage was analysed.

Results: This study included 9863 obesity data (including valid waist circumference and body mass index) and 7496 body fat data. Compared with the inactive group, the weekend warriors and regularly active individuals had lower risks of general and abdominal obesity, as well as reduced body fat. Furthermore, individuals who were insufficiently active but engaged in ≥3 days of MVPA showed significantly lower body fat and obesity risk than their inactive counterparts.

Conclusion: Engaging in physical activity even once or twice a week can positively impact weight control.

Aims: Microvascular complications, such as diabetic retinopathy (DR), diabetic nephropathy (DN) and diabetic peripheral neuropathy (DPN), are common and serious outcomes of inadequately managed type 1 diabetes (T1D). Timely detection and intervention in these complications are crucial for improving patient outcomes. This study aimed to develop and externally validate machine learning (ML) models for self-identification of microvascular complication risks in T1D population.

Materials and methods: Utilizing data from the Chinese Type 1 Diabetes Comprehensive Care Pathway program, 911 T1D patients and 15 patient self-reported variables were included. Combined with XGBoost algorithm and cross-validation, self-identification models were constructed with 5 variables selected by feature importance ranking. For external validation, an online survey was conducted within a nationwide T1D online community (N = 157). The area under the receiver-operating-characteristic curve (AUROC) was adopted as the main metric to evaluate the model performance. The SHapley Additive exPlanation was utilized for model interpretation.

Results: The prevalence rates of microvascular complications in the development set and external validation set were as follows: DR 7.0% and 12.7% (p = 0.013), DN 5.9% and 3.2% (p = 0.162) and DPN 10.5% and 20.4% (p < 0.001). The models demonstrated the AUROC values of 0.889 for DR, 0.844 for DN and 0.839 for DPN during internal validation. For external validation, the AUROC values achieved 0.762 for DR, 0.718 for DN and 0.721 for DPN.

Conclusions: ML models, based on self-reported data, have the potential to serve as a self-identification tool, empowering T1D patients to understand their risks outside of hospital settings and encourage early engagement with healthcare services.

Obesity is a major public health concern and burden on individuals and healthcare systems. Due to the challenges and limitations of lifestyle adjustments, it is advisable to consider pharmacological treatment for people affected by obesity. However, the side effects and limited efficacy of available drugs make the obesity drug market far from sufficient. Drug repurposing involves identifying new applications for existing drugs and offers some advantages over traditional drug development approaches including lower costs and shorter development timelines. This review aims to provide an overview of drug repurposing for anti-obesity medications, including the rationale for repurposing, the challenges and approaches, and the potential drugs that are being investigated for repurposing. Through advanced computational techniques, researchers can unlock the potential of repurposed drugs to tackle the global obesity epidemic. Further research, clinical trials, and collaborative efforts are essential to fully explore and leverage the potential of drug repurposing in the fight against obesity.